The present invention relates to percussive instrument mallets and a method of manufacture thereof, and in particular a mallet with shaft attached to an embedded insert.
Instrument mallets typically have a shaft and a head, and are available in many forms to be played on many kinds of percussive instruments such as assorted drums (marching, tympani, orchestral), xylophone, marimba, vibraphone, bells and the like.
Many mallets, especially those with relatively small shafts (i.e., under 0.5 inches) include a shaft inserted directly into a drilled head which is secured by a nail, screw, adhesive or combination. Mallet heads vary across a wide gamut of shapes, materials and constructions. Heads can be wood, plastic, rubber, felt, and other materials. Often the mallet head is wrapped over with other materials such as yarns or felts. The shafts also vary, with assorted types of wood, plastic, rattan and fiberglass being common. The drilled hole is of similar size to the shaft. Optionally, a lead body or similar weighting member can be added into the hole before the shaft is attached to increase the mass of the mallet head.
A somewhat common drawback of these types of instrument mallets is failure of the connection between the head and shaft after a period of use, thereby allowing the head to come loose from the shaft and rendering the mallet unusable. Additionally, if present, the nail or screw can split the wooden shaft, also leading to failure of the mallet. Glued variations carry additional drawbacks in that many desirable mallet head materials are difficult to adhere to due to their required elasticity and the heavy repeated impacts the mallet must withstand during normal use. This can make it difficult to sufficiently bond a threaded insert into the head to improve the connection.
One attempt to improve the construction of such mallets is disclosed in U.S. Pat. No. 7,439,434. This patent teaches a composite head formed by molding a thermoplastic material completely around a hollow metal insert that is plugged in the mold. After the mold is opened and over-molded plug is withdrawn to reveal the composite head, a shaft is inserted and glued into the insert. The composite head is then wrapped with a resilient material such as yarn. This technique is not amenable to producing composite heads with easily varying head weights. To maintain a good connection between the shaft and insert based on a constant shaft penetration, the size of the insert must vary commensurate with the size of the weight placed within the insert before the shaft is connected.